1. Field of the Invention
This invention relates to a control center and, more particularly, to insulated and isolated horizontal bus bars therein.
2. Description of the Prior Art
In modern electrical apparatus, there is increased attention devoted to operator safety as well as minimizing damage to equipment due to short circuits. In a motor control center, the distribution of power by the bus bar system is a vital factor which influences the whole design concept. More specifically, the horizontal bus bar distributes power to a number of vertical bus bars connected to it. Consequently, there is interaction between the bus bar system and other design-criteria that must be met. Such criteria include insulation and isolation of the three phases to provide operator safety and fault prevention, the provision of adequate cooling means, bracing the horizontal bus bars for various short circuit current withstandability requirements, accommodation of horizontal bus bars of varying ampacities, provision of electrical joints between the horizontal bus and the vertical bus bars, providing splice plate connections for extending the horizontal bus, and permitting bolting of risers/cable lugs for incoming lines.
Patents disclosing insulated bus bars in various aspects are U.S. Pat. Nos. 3,096,131, 3,113,820, 3,170,092, 3,840,785, 4,024,441, and 4,025,826.